Status
Stability	alpha: traces
Distributions	core, contrib
Issues
Code Owners	@boostchicken

The span processor modifies the span name based on its attributes or extract span attributes from the span name. It also allows to change span status. Please refer to config.go for the config spec.

It optionally supports the ability to include/exclude spans.

The following actions are supported:

• name: Modify the name of attributes within a span
• status: Modify the status of the span

The following settings are required:

• from_attributes: The attribute value for the keys are used to create a new name in the order specified in the configuration.

The following settings can be optionally configured:

• separator: A string, which is specified will be used to split values

Note: If renaming is dependent on attributes being modified by the attributes processor, ensure the span processor is specified after the attributes processor in the pipeline specification.

span:
  name:
    # from_attributes represents the attribute keys to pull the values from to generate the
    # new span name.
    from_attributes: [<key1>, <key2>, ...]
    # Separator is the string used to concatenate various parts of the span name.
    separator: <value>

Example:

span:
  name:
    from_attributes: ["db.svc", "operation"]
    separator: "::"

Refer to config.yaml for detailed examples on using the processor.

Takes a list of regular expressions to match span name against and extract attributes from it based on subexpressions. Must be specified under the to_attributes section.

The following settings are required:

• rules: A list of rules to extract attribute values from span name. The values in the span name are replaced by extracted attribute names. Each rule in the list is regex pattern string. Span name is checked against the regex and if the regex matches then all named subexpressions of the regex are extracted as attributes and are added to the span. Each subexpression name becomes an attribute name and subexpression matched portion becomes the attribute value. The matched portion in the span name is replaced by extracted attribute name. If the attributes already exist in the span then they will be overwritten. The process is repeated for all rules in the order they are specified. Each subsequent rule works on the span name that is the output after processing the previous rule.
• break_after_match (default = false): specifies if processing of rules should stop after the first match. If it is false rule processing will continue to be performed over the modified span name.
• keep_original_name (default = false): specifies if the original span name should be kept after processing the rules. If it is true, the original span name will be kept, otherwise it will be replaced with the placeholders of the captured attributes.

span/to_attributes:
  name:
    to_attributes:
      rules:
        - regexp-rule1
        - regexp-rule2
        - regexp-rule3
        ...
      break_after_match: <true|false>
      keep_original_name: <true|false>

Example:

# Let's assume input span name is /api/v1/document/12345678/update
# Applying the following results in output span name /api/v1/document/{documentId}/update
# and will add a new attribute "documentId"="12345678" to the span.
span/to_attributes:
  name:
    to_attributes:
      rules:
        - ^\/api\/v1\/document\/(?P<documentId>.*)\/update$

# This example will add the same new "documentId"="12345678" attribute,
# but now resulting in an unchanged span name (/api/v1/document/12345678/update).
span/to_attributes_keep_original_name:
  name:
    to_attributes:
      keep_original_name: true
      rules:
        - ^\/api\/v1\/document\/(?P<documentId>.*)\/update$

The following setting is required:

• code: Represents span status. One of the following values "Unset", "Error", "Ok".

The following setting is allowed only for code "Error":

• description

Example:

# Set status allows to set specific status for a given span. Possible values are
# Ok, Error and Unset as per
# https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/trace/api.md#set-status
# The description field allows to set a human-readable message for errors.
span/set_status:
  status:
    code: Error
    description: "some error description"

Refer to config.yaml for detailed examples on using the processor.